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61.
UV-B辐射增强对褶皱臂尾轮虫摄食的影响 总被引:4,自引:4,他引:0
运用生态毒理学方法,研究了UV-B辐射条件下褶皱臂尾轮虫(Brachinonus plicatilis)对6株海洋微藻:小球藻(Chlorella sp.、绿色巴夫藻(Pauloua uiridis)、扁藻(Tetraselmis chuii)、球等鞭金藻8701(Isochrysis galbana Park 8701)、牟氏角毛藻(Chaetoceros muelleri Lermumerman)和小新月菱形藻(Nitzschia clostertum)的摄食.结果表明:UV-B辐射增强对褶皱臂尾轮虫的摄食有显著的抑制作用.与对照组相比,褶皱臂尾轮虫对每一种饵料单胞藻的滤水率和摄食率都表现出,随UV-B辐射剂量的增大而显著减小(P<0.5).而且对每一种饵料单胞藻的滤水率和摄食率是不相同的,这说明褶皱臂尾轮虫对饵料单胞藻是有选择性的. 相似文献
62.
In Bureaucratizing the Good Samaritan , Waters (2001) argues that bureaucratic rationality distracts humanitarian agencies from the needs of the people they are supposed to assist, in favour of other values that their institutional frameworks dictate. We test his claim by investigating the response to the Pakistan 2005 earthquake. One of us (Dittemore) worked with the United Nations Joint Logistics Centre in the theatre, managing a relief cargo shipment database. The response, known as 'Operation Winter Race', was hampered by extreme logistical challenges, but ultimately succeeded in averting a second disaster resulting from cold and starvation. We use statistical models to probe whether survivor needs significantly guided decisions to deliver relief to affected communities. Needs assessments remained incomplete and incoherent. We measure needs through proxy indicators and integrate them, on a Geographic Information System (GIS) platform, with logistics and relief delivery data. We find that, despite strong logistics effects, needs orientations were significant. However, the strength of decision factors varies between commodity types (food versus clothing and shelter versus reconstruction materials) as well as over the different phases of the response. This study confirms Thomas's observation that logistics databases are rich 'repositories of data that can be analyzed to provide post-event learning' (Thomas, 2003, p. 4). This article is an invitation for others to engage in creative humanitarian data management. 相似文献
63.
Biological control experiment of excess propagation of Cyclops for drinking water security 总被引:1,自引:0,他引:1
Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this study, an ecological project was put forward for the excess propagation control of Cyclops by stocking the filter-feeding fishes such as silver carp and bighead carp under the condition of no extraneous nutrient feeding. The results of experiments with different stocking biomass showed that the propagation of Cyclops could be controlled effectively, and the water quality was improved simultaneously by impacting on nutriment level and plankton community structure at proper stocking density of 30 g/m^3 of water. The growth of Cyclops may not be effectually controlled with lower biomass of fish (10 g), and the natural food chain relation may be destroyed for Cyclops dying out in water while the intense stocking of 120 g per cubic meter of water. In addition, the high predator pressure may accelerate supplemental rate of nutrients from bottom sediments to water body to add the content of total nitrogen and phosphorus in water. 相似文献
64.
Bioaccumulation of heavy metals in fishes from Taihu Lake, China 总被引:9,自引:0,他引:9
The Cr,Zn,Cu,Cd,Pb contents were determined in Cyprinus carpio Linnaeus,Carassius auratus Linnaeus,Hypophthalmichthys molitrix and Aristichthys nobilis,which were caught from Meiliang Bay,Taihu Lake,a large,shallow and eutrophic lake of China.The results showed that:(1)the Cr,Cu,Pb,Cd contents in the edible parts of the four fish species were much lower than Chinese Food Health Criterion(1994),but the Zn contents were higher than the Criterion;(2)Cd contents were the highest in the liver of fish,Pb contents were almost the same in all organs of fish,Cr contents mainly enriched in the skin and gonads,Zn contents were the highest in the gonad(♀),and Cu contents were the highest in the liver;(3)the total metal accumulation was the greatest in the liver and the lowest in the muscle.The total metal accumulation was the highest in C.auratus L.This investigation indicated that fish products in Taihu Lake were still safe for human consumption,but the amount consumed should be controlled under the Chinese Food Health Criterion to avoid excessive intake of Zn. 相似文献
65.
水-粮食贸易:虚拟水研究进展 总被引:18,自引:0,他引:18
虚拟水思想强调的是水资源贡献,量化计算是其深入研究的基本,而是否选择虚拟水作为战略政策,应该考虑由不同国家的资源贡献和生产技术决定的比较利益。社会调适能力要求社会针对资源的第一性缺乏做相应调适并谋求解决手段,以提高资源管理能力。为此,需要结合我国的水和粮食安全问题,提出用虚拟水贸易解决我国水资源和粮食问题,提高我国对水资源缺乏的调适能力。 相似文献
66.
Management of an Agroecosystem 总被引:4,自引:0,他引:4
Agroecosystems (AESs) are autotrophic ecosystems managed by man. The goal of the management is to obtain the maximum possible amount of high-quality agricultural products while preserving agricultural resources, primarily the soils and biodiversity. The main components of the management of AES structures and functions, including primary and secondary biological production, the ratio between the energy flows in the plant–man and plant–livestock–man food chains, the efficiency of energy transfer in the plant–livestock link, and conservation of agricultural resources, are considered. 相似文献
67.
Food and food-related waste is a high priority in terms of waste minimisation in New Zealand. Over the summer of 2012–2013, a survey of 147 participants was conducted on a range of views and practices related to environmental challenges and understandings. The survey, undertaken in Palmerston North, New Zealand, captured a wide socio-demographic. This article focuses on respondents’ food practices from purchase, to plate, to disposal and the environmental implications of these practices. The survey data have allowed an enriched understanding of both individual and structural level challenges as well as incentives towards improving environmental practices in relation to household food waste minimisation. The results indicated that, in keeping with other research in this area, food waste increases according to the number of individuals in a household, and in particular the number of younger people. Also, while the majority of participants were at least “somewhat concerned” about their households’ environmental impact, over three quarters of participant households put food waste into their rubbish bin. Some solutions and directions to further progress research, policy, and practice in this area are offered, and include the need for more direct and personalised communication regarding waste minimisation, along with the provision of kerbside food waste collections. It is clear that individual- or household-level changes are important and must be supported systemically by both local body and state level legislation and initiatives, if there is to be any substantial decline in food waste going to landfill. 相似文献
68.
Marcela Capcarova Katarina Zbynovska Anna Kalafova Jozef Bulla Peter Bielik 《Journal of environmental science and health. Part. B》2016,51(4):236-244
The contamination of food and feed by mycotoxins as toxic metabolites of fungi is a risk not only for consumers resulting in various embarrassment regarding health status and well-being, but also for producers, companies and export market on the ground of economic losses and ruined stability of economic trade. As it is given in historical evidence, the contamination of food by mycotoxins is a topic as old as a history of mankind, finding some evidence even in the ancient books and records. Nowadays, the mycotoxins are used in modern biotechnological laboratories and are considered an agent for targeting the specific cells (e.g., defected cells to eliminate them). However, this promising procedure is only the beginning. More concern is focused on mycotoxins as abiotic hazard agents. The dealing with them, systematic monitoring, and development of techniques for their elimination from agricultural commodities are worldwide issues concerning all countries. They can be found alone or in co-occurrence with other mycotoxins. Thus, this review aims to provide widened information regarding mycotoxins contamination in environment with the consequences on health of animals and humans. The inevitability for more data that correctly determine the risk points linked to mycotoxins occurrence and their specific reactions in the environment is demonstrated. This review includes various symptoms in animals and humans that result from mycotoxin exposure. For better understanding of mycotoxin's impact on animals, the sensitivities of various animal species to various mycotoxins are listed. Strategies for elimination and preventing the risks of mycotoxins contamination as well as economical approach are discussed. To complete the topic, some data from past as historical evidences are presented. 相似文献
69.
汶川地震极重灾区地形起伏度特征及其与生态环境受损关联分析 总被引:3,自引:0,他引:3
采用DEM数据对汶川地震极重灾区地形起伏度特征分析,海拔高度和地形起伏度总体上是南西高,北东低。5km×5km单元地形起伏度〉1000m的区域面积占27.98%。0.5km×0.5km单元〉100m的区域面积占50.63%。在8.0级主震和6.4级余震震中之间典型区段剖面0.5km间隔分析中,南西段起伏度大于北东段,南西段起伏度〉200m区段占全段14.84%,北东段仅占6.64%。地震导致生态环境受损程度的差异与地形起伏度的差异在空间分布上有一定的重合,具有高起伏度的南西段生态系统破坏面积占总破坏面积的88.55%,新增水土流失面积占新增总面积的70.99%。地震灾区地形起伏度是生态环境遭受严重破坏致灾关联因素之一。 相似文献
70.
虹膜识别在肉类食品安全追溯系统中的应用及关键技术研究 总被引:6,自引:2,他引:4
为了提高大型动物肉类食品的安全性,在研究肉类食品供应链的安全管理的基础上,将大型动物的虹膜识别技术引入食品供应链管理中,构建基于虹膜识别的大型动物肉类食品安全可追溯系统,达到肉类食品安全信息查询及出现安全问题后的个体溯源的目的。借鉴人眼虹膜识别的相关技术,以牛眼为例对大型动物虹膜识别的相关算法和虹膜定位等关键技术进行研究,运用改进的Sobel算子对图像进行边缘检测;引入二次B样条曲线算法实现了牛眼虹膜的精确定位;分析牛虹膜纹理特征的分布特点,实现了虹膜特征区域的提取及归一化处理。研究成果对大型动物的虹膜识别研究和肉类食品供应链安全管理具有一定的参考意义。 相似文献